Collaborative Research: geophysical evaluation of biogenic gases in peatlands

0510370 0510545 0510004斯莱特 Glaser ReeveBiogenic气体排放从北方泥炭地，从维管植物的芯吸和由情节沸腾事件，占约7%的全球每年甲烷排放到大气中。该建议涉及应用探地雷达（GPR）的实验，用于（1）估计储存在泥炭地中的生物成因气体的量，（2）确定泥炭内生物成因气体的空间分布，以及（3）监测生物成因气体释放到大气中。缅因州北方大泥炭地（CN-0242353）的数据表明：（1）较高的CH 4和CO2浓度与井间探地雷达数据中的高速度/高衰减区以及地面探地雷达数据中的阴影区（反射损失）相关;（2）在该泥炭地采集的+11 km地面探地雷达数据中经常观察到阴影区（指示高气体含量）。实验目标是：（1）对泥炭芯从地表到矿质土壤剖面的介电常数与气体含量之间关系的实验室评价：（2）通过测量水位、水力传导率和时域反射仪，进行跨孔和地表探地雷达监测实验，观察生物气体释放到大气中的速率;（3）地面探地雷达研究，结合生物气浓度的现场测量，估算了两个已研究的北方泥炭地（缅因州Caribou沼泽和明尼苏达州Glacial Lake Agassiz）中生物气的储存量。重要的里程碑包括：（a）根据介电常数测量值，估算泥炭中气体含量的预测方程，作为深度的函数，（B）对泥炭地气体释放和吹泡通量的时间模式的新认识，以及（c）对泥炭地碳储层中自由气体含量的新估计，说明气体的空间/深度分布。在应用研究框架内开展社区外联和国际合作。来自罗格斯-纽瓦克荣誉学院（HC）的荣誉本科生（HUG）研究人员将与博士后科学家合作，以获得完成四项主要研究任务所需的研究培训。每个HUG将完成一个为期一年的高级项目对他们的研究和贡献的出版物。罗格斯-纽瓦克大学在校园UG多样性方面是美国国立大学中排名第一的大学，这为少数民族学生提供了巨大的机会。罗格斯-纽瓦克大学地球/环境科学专业的学生经常表示对实地考察经验感兴趣。部分野外工作将由参加新课程的学生进行，该课程是作为本项目的一部分开发的地球物理学夏令营。社区宣传将通过导游、海报板和关于驯鹿沼泽地水文、生态和碳循环的介绍进行，最近开放的2公里长的奥罗诺木板路为公众提供了进入这片沼泽地的机会。最后，与欧洲一位杰出的泥炭地科学家的合作将吸引国际社会对我们工作的关注，并提供一个机会，对一个独特的欧洲泥炭沼泽进行比较研究。

0510370 0510545 0510004Slater Glaser ReeveBiogenic gas emission from northern peatlands, by wicking from vascular plants and byepisodic ebullition events, accounts for approximately 7% of the global annual emissionof methane to the atmosphere. This proposal involves experiments to apply groundpenetrating radar (GPR) for (1) estimating the amount of biogenic gas stored in peatlands,(2) determining the spatial distribution of biogenic gas within the peat, and (3)monitoring biogenic gas release to the atmosphere. Data from a large northern peatland inMaine (EAR-0242353) show that (1) higher CH4 and CO2 concentrations correlate withhigh velocity/high attenuation zones in cross-borehole GPR data as well as shadow zones(loss of reflections) in surface GPR data, (2) shadow zones (indicative of high gascontent) are frequently observed in the +11 km of surface GPR data collected in thispeatland. The experimental objectives are: (1) a laboratory evaluation of the relationshipbetween dielectric permittivity and gas content for a profile of peat cores from the surfaceto the mineral soil; (2) a cross-hole GPR and surface GPR monitoring experiment,supported by measurements of water levels, hydraulic conductivity and time domainreflectometry, to observe rates of biogenic gas release to the atmosphere; (3) a surfaceGPR study, supported by in situ measurements of biogenic gas concentration, to estimatethe volume of biogenic gas stored in two well studied northern peatlands (Caribou Bog,ME and Glacial Lake Agassiz, MN). Important milestones include (a) a predictiveequation for gas content estimation in peat as a function of depth from dielectricpermittivity measurements, (b) new insight into the temporal pattern of gas release andebullition flux from peatlands, and (c) new estimates of the free gas content of peatlandcarbon reservoirs accounting for the spatial/depth distribution of the gas.Broader ImpactsThis proposal incorporates educational activities, curriculum development, communityoutreach and international collaboration within an applied research framework. HonorsUnderGraduate (HUG) researchers from the Rutgers-Newark Honors College (HC) willpartner with a postdoctoral scientist to obtain the research training required to completefour of the primary research tasks. Each HUG will complete a yearlong senior project ontheir research and contribute to a publication. The status of Rutgers-Newark as the toprankedNational US University with respect to campus UG diversity facilitates HUGopportunities to minority students. Students in Earth/Environmental Sciences at Rutgers-Newark frequently express interest in fieldwork experiences. Part of the fieldwork will beconducted by students participating in a new class, Summer Field Camp in AppliedGeophysics, developed as part of this project. Community outreach will occur via guidedtours, poster boards and presentations on the hydrology, ecology and carbon cycle inCaribou Bog, facilitated by the recently opened 2 km long Orono boardwalk that nowprovides public access to this bog. Finally, collaboration with a prominent peatlandscientist in Europe will draw international attention to our work and provide anopportunity to conduct comparative work on a unique European peat bog.